Soft start or vfd

[mksj]

Disappointing about Wolf Automation technical, seems like who you get, others have have mentioned they have been more helpful. Might go to some third party these days. The AuCom seemed to check all the boxes. I like Automation Direct, I use them a lot for automation/control system parts, so glad they could provide more information. The SR33-41 should work if you motor draws 29-30A under full load, the load would be rated class 20 from the description. SR33-55 would be indicated it your motor FLA is over 30A. Frequency of starts is 5 per hour, but this will also be influenced by many other factors, the rated starting capacity for class 20 is 4X the motor current for 19 seconds, I would assume if one shortens the starting time or decreases the starting current it would lower the thermal impact and allow more start stop cycles. Still seems like a SS is an easier install than a VFD.

 

[sdelivery]

can't work that way unless you want to lose some fingers or hands along with destroying the work piece. can't set a 50-300# (+) workpiece on a moving belt

Then put a clutch on the moving belt drive?
Or maybe on the motor to the drive.
The rest of the industrial world has learned to stop and start the largest equipment safely.

 

[deakin]

Disappointing about Wolf Automation technical, seems like who you get, others have have mentioned they have been more helpful. Might go to some third party these days. The AuCom seemed to check all the boxes. I like Automation Direct, I use them a lot for automation/control system parts, so glad they could provide more information. The SR33-41 should work if you motor draws 29-30A under full load, the load would be rated class 20 from the description. SR33-55 would be indicated it your motor FLA is over 30A. Frequency of starts is 5 per hour, but this will also be influenced by many other factors, the rated starting capacity for class 20 is 4X the motor current for 19 seconds, I would assume if one shortens the starting time or decreases the starting current it would lower the thermal impact and allow more start stop cycles. Still seems like a SS is an easier install than a VFD.

auto direct had a selector guide. one question was elevation above sea level. that was never covered in my 60's electronics classes

 

[sdelivery]

Not all compressors have an unloader valve, mine don't , so it always starts under load.
It looks like deakin's machine also needs to start under load.

Even the cheapest compressors have an unloader. With some it is on the head(valves) some Its built into some of the pressure switches.

 

[deakin]

Then put a clutch on the moving belt drive?
Or maybe on the motor to the drive.
The rest of the industrial world has learned to stop and start the largest equipment safely.

easier said than done. would have to be a slipping clutch or the workpiece and i would be thrown across the room

 

[mksj]

Yes, they have a nice calculator to determine the size of the SS. As mentioned the calculator may be based on maximum values, so there may be some wiggle room on the start/stop cycles. The AuCom is not limited to starts per hour.

Soft Starters Selector | AutomationDirect

www.automationdirect.com

 

[sdelivery]

You mean like a part on an old VTL?
Many of the large lathes used a mechanical clutch to start the load , this way the operator could ease it up to speed.
Many cranes are using both friction clutches as well.
Monarch lathe company uses an easy to make style, I know of 30 HP on one of them. And adjustable when it starts to wear.

 

[deakin]

You mean like a part on an old VTL?
Many of the large lathes used a mechanical clutch to start the load , this way the operator could ease it up to speed.
Many cranes are using both friction clutches as well.

think of an engine block on a very large belt sander. two hands holding on to the block, one foot on the switch, the other foot keeping the operator vertical - out of hands and feet

 

[sdelivery]

think of an engine block on a very large belt sander. two hands holding on to the block, one foot on the switch, the other foot keeping the operator vertical - out of hands and feet

Sounds like someone needs to stand back and engineer some solutions to the process.
It also sounds like it is just a matter of time before someone gets hurt.

 

[deakin]

Sounds like someone needs to stand back and engineer some solutions to the process.
It also sounds like it is just a matter of time before someone gets hurt.

they have been using this type machine in eng rebuilder shops for a long time. i bought this new in 1985. used it almost daily back in the day. never got hurt. can't say the same about dirt bikes.

i don't believe it is nec to reinvent it. only issue with it now is power or lack of